This invention relates generally to electric power generation, and more particularly to a gear drive apparatus for electric power generators.
The use of wind turbines for generating electrical power is well known. A conventional wind turbine includes a nacelle mounted atop a tall tower. The nacelle carries a turbine rotor at one end. Inside the nacelle, a rotor shaft couples the rotor to a gearbox, which is in turn coupled to a separate electrical generator. This leads to a long drivetrain. As a result, the element that provides structural support to the rotor, gearbox, and generator, referred to as a “bedplate,” is quite large and heavy, as is the nacelle.
In operation, wind forces acting on the nacelle cause deflection of the bedplate. This leads to misalignment between axes of the rotor shaft and the gearbox. The input shaft bearings of the gearbox have to carry the load imposed by this misalignment. In essence, the rotor shaft bearings and the input shaft bearings of the gearbox are “fighting” each other. This leads to excessive wear or damage, or requires the use of excessively heavy and expensive components if they are over-designed to withstand such loads.